Process of making soap



i Patented July 7, 1931 UNITED STATES.

JOHN E. BUTZLER, JR OF ARLINGTON, NEW JERSEY rnoonss OF MAKING soar Io Drawing.

M invention relates to a process of soap makm in which light colored soaps may be made rom dark or discolored soap stock such as cotton oil foots, No. 3 tallow, acidified wool 6 fat, acidulated coconut oilsoap stock, etc., and more particularly to a process in which hydrogen peroxide may be effectively used in forming a light colored soap from stocks of the above type.

In soap making processes heretofore used, when a dark colored or discolored soap stock is employed, the resulting soap has acorrespondingly undesired dark color unless the stock is purified prior to its use as a soap stock. The purification of such dark colored stocks by the usual processes is, however, expensive and unsatisfactory. Because of this expense in purification, the utilization ofthese dark or discolored stocks for the production of white soaps of good appearance has heretofore been economically impracticable.

An object of my invention is to provide a process in which dark colored soap stocks may be used directly for the production of a white, or substantiall white, soap.

Another object of the invention is to provide a process by which the coloring matter of naturally dark or discolored oils and fats may be destroyed and removed during the soap making. a

As a bleachin agent for fatty materials of the above in icated type, hydrogen peroxide is free from disadvantages inherent in many other oxidizing agents as it cannot leave dissolved, or otherwise retained, in the product any deleterious ordisagreeable substances, and does not form with the fatty materials any combinationsthat would injuriously altertheir character or impair their quality. When used in the ordinary manner for the purpose of oxidizing the coloring matter of, or otherwise bleaching, thesesoa stocks, however, hydrogen peroxide is, in general, ineffective and fails to accomplish any substantial and permanent bleaching, particularly on such stocks as No. 3 tallow, cotton seed oil foots, acidulated coconut oil soa stocks, or wool fat."

A further ob ect of my invention is, thereand to e Application filed September 28, 1928. Serial No. 309,126.

fore, to provide a process for effectively and permanently bleaching discolored soap stock by means of hydrogen peroxide.

Still further objects and features .of. the invention are to provide a process of making soap from discolored soap stocks in which the stock is bleachedduring the soap making operations and in which the coloring mawith hydrogen peroxide, or an equivalent peroxide, in an alkaline solution, preferably in a solution of sodium hydroxide or carbonate. Under these conditions the peroxide, or the sodium peroxide which is formed or the nascent oxygen derived therefrom, has a strong oxidizing action and effectively and permanently oxidizes the coloring matter in the stock. The alkali is in excess of that required to saponify'the fat or neutralize the fatty acids and thus produce a soap. Therefore, it is apparent that in this process the bleaching of the soap stock is carried. out simultaneously with the production of the soap from said stock. The simultaneous saponification, neutralization and bleaching may be accomplished by the cold process in certain instances, or by the full boiled process, or the-fats may;be hydrolized by the Twitchell, Krebitz, or any other suitable hydrolizing process, and the resulting fatty acid may be neutralized in the cold with alkalies. To remove any of the unoxidized' or otherwise unchanged coloring matter, the soap or saponified fats may be dissolved in water, which is alkaline, and then salted out with any suitable salt such as sodium chloride or sodium sulfate, any residual coloring constituents being largely retained in the water from which the soap separates. The alkalinity of the water appears to cut down the absorgption of coloring matter by the soap ect a better separation of the soap from the water solution. The soap stocks I from sodium peroxide, or in other ways, a

suitable solution can be most easily and conveniently formed by dissolving the hydrogen peroxide in a solution of sodium hydroxide.

In the preferred manner of carrying on the process, however, as illustrated by way of example in the following instances, the hy-' drogen peroxide is mixed or emulsified in the soap stock and the alkali is added to this emulsion, or the emulsion may be added to an alkali solution. I

Example I 4 litres of a 7 75 hydrogen peroxide solution are emulsified with 25 kgsQof acidulated coconut oil soap stock, that is, a soap stock consistinglargely of the fatty acid content of coconut oil. The acidulated coconut oil soap stock is commonly obtained in the refining of coconutoil by treating the oil with a small amount of caustic alkali, separating the product from the oil and acidifying, thereby liberating the fatty acids. To-this emulsion there areadded, with violent stirring or agitation, 5 litres of a 50% sodium hydroxide solution. This solution contains about 4.24 kgs. of total NaOH. The agitation of the mixture is. continued for a very short time after all of the sodium hydroxide solution hasbeen added or until the mass becomes stifi', for example, about twenty minutes. The mixture is then allowed to stand for a sufficient length of time to allow the hydrogen peroxide to decompose and to react with the coloring matter in theoil.

The soap which has been formed is now dissolved in a small amount of Water, for example, about 100 litres. To the resulting solution there are added 4 litres of 7 hydrogen peroxide solution and 2.6 litres of a sodium hydroxide solution containing a total of 2 kgs. of pure NaOH. When this mixture has stood for about half an hour, 150 litres of water are added. The soap is then salted out b the usual methods, that is, by adding soli common salt or a concentrated salt solution. On the basis of a molecular weight of 200 for the coconut oil acids the sodium hydroxide usedin this example is 160% of the amount theoretically required. Saponified wool fat and other fats may also be used in this example.

E wa/mple I I ide solution. To this emulsion are then added, with violent agitation, 6 litres of a50% sodium hydroxide solution. The resulting mixture -is allowed to stand for one hour while maintained at a temperature of about G.7 0 C. by suitable means. Thereupon the mixture is dissolved in 200 litres of water and 5 litres of a 7 hydrogen peroxide solu-l tion, and 2 litres of a50 sodium hydroxide solution are added. The mixture is kept well agitated during this operation. After standing for sometime, 450 litres of water are added and the mixture is warmed to 45 0.,-

Ewmnple 11 1 20 kgs. of No. 3 tallow are mixed with 10 kgs. of acidulated coconut oil soap stock and emulsified with 5 -litre's of 7%% hydrogen peroxide solution. '6 litres of 50% sodium hydroxide solution are then slowly added to the emulsion with violent agitation. This quantity of the sodium hydroxide solution contains 5.02 kgs. of NaOH. After the agitation is completed the mixture is allowed to stand until saponification is substantially complete. The time for this varies according to the size and nature of the charge, but in the example given is about one hour at about 60 C. The soap is now put into solution in 200 litres of water, and 6 kgs. of sodium hydroxide are then added to the mixture in the form of a 50% solution. 5 litres of 7 hydrogen peroxide solution are now added. After the reaction is completed the soap may be separated from the solution by salting out in the usual manner. In this example the amount of sodium hydroxide used is 210.7% of that theoretically required for the stock.

Instead of the proportions of tallow and coconut oil described above, a mixture of soap stock containing 22 kgs. of No. 3 tallow and 3.8 kgs. eachof cotton seed oil foots and acidulated coconut oil soap stocks may be employed. The proportions of acidified coconut oil soap stock and No. 3 tallow may be varied continuously. The same excess of sodium hydroxide is used as above. Castor oil may be used alone, or in other mixtures as in the above example.

Example I V A light colored full boiled soap may be prepared from No. 3 tallow and acidulated coconut oil soap stock in the following manner: A mixture containing 20 kgs. of No. 3

tallow and 10 kgs. of acidulated coconut oil soap stock is added to 1200 litres of water and is heated. 12.9 litres of 50% sodium hydroxide solution, or its equivalent in solid sodium hydroxide, are then added to the system, preferably near the boiling point. The system is then heated to boiling and there are added, well under the surface of the li uid, 2 litres of 7 h drogen peroxide. t intervals of one-hal hour or longer there are then added three successive 3 litre portions of 7 hydrogen peroxide, the hydrogen peroxide being introduced well below the surface of the solution as described above. After the last addition of the hydrogen peroxide, the solution is boiled for one-half to three quarters of an hour, the volume of liquid in the apparatus being maintained by the addition of water from time to time. The solution is now allowed to cool somewhat and the soap is then salted out with sodium chloride.

The time factors may be varied in the above examples to suit different conditions obtaining when different quantities of the various stocks are used or other conditions are varied. The concentration of the sodium hydroxide solution may be varied from the examples given above and, under suitable conditions, solid caustic may be employed. The concentration of hydrogen peroxide may vary from that given in the above examples. The temperature conditions may also be Varied to suit varying requirements and the'system may be agitated mechanically or otherwise as conditions may require.

As changes of operation can be made within the scope of my invention, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense. y

Having now described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A process of making soap which comprises saponifying a fat 1n an alkaline peroxide solution.

2. A process of bleaching discolored fats and fatty acids which comprises treating the fatty materials with an alkaline peroxide solutionin the presence of an excess of alkali and under saponifyin conditions.

3. A process of ma 'ng' soap which comprises treating a soap stock with a solution of hydrogen peroxide and an alkali,'the quantity of said alkali exceeding by over twenty per cent the amount required to neutralize the acid of said soap stock.

4. A process of making soap which com prises treating soap stock with a solution of ydrogen peroxide and sodium hydroxide, the quantity of said sodium hydroxide exceeding by over twenty per cent the amount required to neutralize the acid of said soap stock.

5. A process ofmaking soap which comprises treating soap stock with a solution of hydrogen peroxide and an alkali, thequan prises treating a soap stock with hydrogen said solution.

tity of alkali in said solution being in substantial excess of that required to neutralize the acid of said soap stock.

6. A process of making soap which comperoxide and a concentrated solution of sodium hydroxide, the quantity o-f said sodium hydroxide solution being in excess of that required to neutralize the acid of said soap stock 7. A process of making soa which comprises treating a soap stock wlth a solution of hydrogen peroxide and sa onifying said stock with alkali in excess of t at required to neutralize the acid of said stock, dissolving the resulting soap in water, and salting said soap from said water.

8. A process of making soap which comprises emulsifying an acidulated soap stock 1 with a hydrogen peroxide solution, and treating with concentrated alkaline solution in excess of that required to neutralize the acid of said stock. l

9. A process of making soap which'comprises emulsifying fatty acids with a hydrogen peroxide solution, and treating with 50% sodium hydroxide solution, the amount of hydroxide in said solution exceeding by over twenty per cent that required to neutralize the acids of said stock.

10. A process of making soap which complrises forming an emulsion of soa stock and ydrogen peroxide, treating said smulsion with a concentrated alkali solution, treating with an additional solution of alkali and hy- 10o drogen peroxide, the quantity of alkali exceeding by twenty per cent that required to neutralize the acids of said stock, dissolving the resulting soap, and salting said soap from- 11. A process of-makin soap which comprises heating a soap stoc in a solution of sodium'hydroxide in amount exceeding by twenty .per cent that required to neutralize the acids of said stock, gradually adding hy- 11 drogen peroxide solution to said alkaline solution, maintaining said alkaline hydroxide and soap stock at an elevated temperature, permitting said mixture of alkaline solution and soap stock to cool, and salting the resulting 116 'soap therefrom.

12. A process of soap making which comprises combining a soap stock with an alkali 1n the presence of an active peroxide, said alkali being in substantial excess of that} 120' quired to neutralizethe acids of said s stock.

In testimony whereof I hereunto aflix-my signature.

- v JOHN E. RUTZLER IR. 

